Nanomedicine Applications of Hybrid Nanomaterials Built from Metal-Ligand Coordination Bonds: Nanoscale Metal-Organic Frameworks and Nanoscale Coordination Polymers

Amino Acid Metabolism-Regulated Nanomedicine for Enhanced Tumor Immunotherapy through Synergistic Regulation of Immune Microenvironment

The reprogramming of tumor metabolism presents a substantial challenge for effective immunotherapy, playing a crucial role in developing an immunosuppressive microenvironment. In particular, the degradation of the amino acid L-tryptophan (Trp) to kynurenine (Kyn) by indoleamine-pyrrole 2,3-dioxygenase 1 (IDO1) is one of the most clinically validated pathways for immune suppression. Thus, regulating the Trp/Kyn metabolism by IDO1 inhibition represents a promising strategy for enhancing immunotherapy. Herein, metabolism-regulated nanoparticles are prepared through metal coordination-driven assembly of an IDO1 inhibitor (NLG919) and a stimulator of interferon genes (STING) agonist (MSA-2) for enhanced immunotherapy. After intravenous administration, the assembled nanoparticles could efficiently accumulate in tumors, enhancing the bioavailability of NLG919 and down-regulating the metabolism of Trp to Kyn to remodel the immunosuppressive tumor microenvironment. Meanwhile, the released MSA-2 evoked potent STING pathway activation in tumors, triggering an effective immune response. The antitumor immunity induced by nanoparticles significantly inhibited the development of primary and metastatic tumors, as well as B16 melanoma. Overall, this study provided a novel paradigm for enhancing tumor immunotherapy through synergistic amino acid metabolism and STING pathway activation.

Prospects, advances and biological applications of MOF-based platform for the treatment of lung cancer

Nowadays in our society, lung cancer is exhibiting a high mortality rate and threat to human health. Conventional diagnostic techniques used in the field of lung cancer often necessitate the use of extensive instrumentation, exhibit a tendency for false positives, and are not suitable for widespread early screening purposes. Conventional approaches to treat lung cancer primarily involve surgery, chemotherapy, and radiotherapy. However, these broad-spectrum treatments suffer from drawbacks such as imprecise targeting and significant side effects, which restrict their widespread use. Metal-organic frameworks (MOFs) have attracted significant attention in the diagnosis and treatment of lung cancer owing to their tunable electronic properties and structures and potential applications. These porous nanomaterials are formed through the intricate assembly of metal centers and organic ligands, resulting in highly versatile frameworks. Compared to traditional diagnostic and therapeutic modalities, MOFs can improve the sensitivity of lung cancer biomarker detection in the diagnosis of lung cancer. In terms of treatment, they can significantly reduce side effects and improve therapeutic efficacy. Hence, this perspective provides an overview concerning the advancements made in the field of MOFs as potent biosensors for lung cancer biomarkers. It also delves into the latest research dealing with the use of MOFs as carriers for drug delivery. Additionally, it explores the applications of MOFs in various therapeutic approaches, including chemodynamic therapy, photodynamic therapy, photothermal therapy, and immunotherapy. Furthermore, this review comprehensively analyses potential applications of MOFs as biosensors in the field of lung cancer diagnosis and combines different therapeutic approaches aiming for enhanced therapeutic efficacy. It also presents a concise overview of the existing obstacles, aiming to pave the way for future advancements in lung cancer diagnosis and treatment.

Drug carrier wonders: Synthetic strategies of zeolitic imidazolates frameworks (ZIFs) and their applications in drug delivery and anti-cancer activity

With the rapid advancement of nanotechnology, stimuli-responsive nanomaterials have emerged as a feasible choice for the designing of controlled drug delivery systems. Zeolitic imidazolates frameworks are a subclass of Metal-organic frameworks (MOFs) that are recognized by their excellent porosity, structural tunability and chemical modifications make them promising materials for loading targeted molecules and therapeutics agents. The biomedical industry uses these porous materials extensively as nano-carriers in drug delivery systems. These MOFs not only possess excellent targeted imaging ability but also cause the death of tumor cells drawing considerable attention in the current framework of anticancer drug delivery systems. In this review, the outline of stability, porosity, mechanism of encapsulation and release of anticancer drug have been reported extensively. In the end, we also discuss a brief outline of current challenges and future perspectives of ZIFs in the biomedical world.

Strategies for the development of metalloimmunotherapies

Metal ions play crucial roles in the regulation of immune pathways. In fact, metallodrugs have a long record of accomplishment as effective treatments for a wide range of diseases. Here we argue that the modulation of interactions of metal ions with molecules and cells involved in the immune system forms the basis of a new class of immunotherapies. By examining how metal ions modulate the innate and adaptive immune systems, as well as host-microbiota interactions, we discuss strategies for the development of such metalloimmunotherapies for the treatment of cancer and other immune-related diseases.

Smart controlled-release nanopesticides based on metal-organic frameworks

The practical utilization rates of conventional pesticide formulations by target organisms are very low, which results in the pollution of ecological environments and the formation of pesticide residues in agricultural products. Water-based nanopesticide formulations could become alternative and effective formulations to eventually resolve the main issues of conventional pesticide formulations. In this feature article, we describe the design concept of smart (stimuli-responsive) controlled-release nanopesticides, which are created toward hierarchical targets (pests, pathogens, and foliage) in response to multidimensional stimuli from physiological and environmental factors (such as sunlight) of target organisms and plants, for achieving enhanced insecticidal and fungicidal efficacies. The pore sizes and functionalities of metal-organic frameworks (MOFs) can be fine-tuned through the choice of metal-containing units and organic ligands. Tailor-made MOF nanoparticles with large microporous or mesoporous sizes, as well as good biocompatibility and high thermal, mechanical, and chemical durabilities, are used to load pesticides within these pores followed by coating of plant polyphenols and natural polymers for stimuli-responsive controlled pesticide release. This feature article highlights our works on smart controlled-release MOF-based nanopesticides and also includes related works from other laboratories. The future challenges and promising prospects of smart controlled-release MOF-based nanopesticides are also discussed.

Metal-Drug Coordination Nanoparticles and Hydrogels for Enhanced Delivery

Drug delivery is a key component of nanomedicine, and conventional delivery relies on the adsorption or encapsulation of drug molecules to a nanomaterial. Many delivery vehicles contain metal ions, such as metal-organic frameworks, metal oxides, transition metal dichalcogenides, MXene, and noble metal nanoparticles. These materials have a high metal content and pose potential long-term toxicity concerns leading to difficulties for clinical approval. In this review, recent developments are summarized in the use of drug molecules as ligands for metal coordination forming various nanomaterials and soft materials. In these cases, the drug-to-metal ratio is much higher than conventional adsorption-based strategies. The drug molecules are divided into small-molecule drugs, nucleic acids, and proteins. The formed hybrid materials mainly include nanoparticles and hydrogels, upon which targeting ligands can be grafted to improve efficacy and further decrease toxicity. The application of these materials for addressing cancer, viral infection, bacterial infection inflammatory bowel disease, and bone diseases is reviewed. In the end, some future directions are discussed from fundamental research, materials science, and medicine.

Nanoparticles Synergize Ferroptosis and Cuproptosis to Potentiate Cancer Immunotherapy

The recent discovery of copper-mediated and mitochondrion-dependent cuproptosis has aroused strong interest in harnessing this novel mechanism of cell death for cancer therapy. Here the design of a core-shell nanoparticle, CuP/Er, for the co-delivery of copper (Cu) and erastin (Er) to cancer cells for synergistic cuproptosis and ferroptosis is reported. The anti-Warburg effect of Er sensitizes tumor cells to Cu-mediated cuproptosis, leading to irreparable mitochondrial damage by depleting glutathione and enhancing lipid peroxidation. CuP/Er induces strong immunogenic cell death, enhances antigen presentation, and upregulates programmed death-ligand 1 expression. Consequently, CuP/Er promotes proliferation and infiltration of T cells, and when combined with immune checkpoint blockade, effectively reinvigorates T cells to mediate the regression of murine colon adenocarcinoma and triple-negative breast cancer and prevent tumor metastasis. This study suggests a unique opportunity to synergize cuproptosis and ferroptosis with combination therapy nanoparticles to elicit strong antitumor effects and potentiate current cancer immunotherapies.

Ultrastable Copper Iodide Hybrid with Intrinsic Greenish White-Light Emission by Incorporating an Anionic Inorganic Functional Unit into an Extended Structure

Incorporating a functional unit into the multidimensional coordination polymer skeleton is an efficient way to improve the stability of materials and expand their application. In this paper, anionic copper iodide inorganic functional modules are incorporated into one-dimensional extended chains by using a unique bidentate cationic organic ligand. Benefiting from the ionic extended structure, the resulting hybrid possesses a remarkable stability with a decomposition temperature as high as 300 °C. Meanwhile, the hybrid material exhibits intrinsic greenish white-light emission with a high photoluminescent quantum yield of 70%. The emission was investigated by temperature-dependent emission spectra, which proved to be the result of the synergistic effect of two energy states. The novel synthetic strategy provides an efficient route for the development of functional organic metal halides.

Exosomes encapsulated in hydrogels for effective central nervous system drug delivery

The targeted delivery of pharmacologically active molecules, metabolites, and growth factors to the brain parenchyma has become one of the major challenges following the onset of neurodegeneration and pathological conditions. The therapeutic effect of active biomolecules is significantly impaired after systemic administration in the central nervous system (CNS) because of the blood-brain barrier (BBB). Therefore, the development of novel therapeutic approaches capable of overcoming these limitations is under discussion. Exosomes (Exo) are nano-sized vesicles of endosomal origin that have a high distribution rate in biofluids. Recent advances have introduced Exo as naturally suitable bio-shuttles for the delivery of neurotrophic factors to the brain parenchyma. In recent years, many researchers have attempted to regulate the delivery of Exo to target sites while reducing their removal from circulation. The encapsulation of Exo in natural and synthetic hydrogels offers a valuable strategy to address the limitations of Exo, maintaining their integrity and controlling their release at a desired site. Herein, we highlight the current and novel approaches related to the application of hydrogels for the encapsulation of Exo in the field of CNS tissue engineering.

A biomimetic camouflaged metal organic framework for enhanced siRNA delivery in the tumor environment

Gene silencing through RNA interference (RNAi), particularly using small double-stranded RNA (siRNA), has been identified as a potent strategy for targeted cancer treatment. Yet, its application faces challenges such as nuclease degradation, inefficient cellular uptake, endosomal entrapment, off-target effects, and immune responses, which have hindered its effective delivery. In the past few years, these challenges have been addressed significantly by using camouflaged metal-organic framework (MOF) nanocarriers. These nanocarriers protect siRNA from degradation, enhance cellular uptake, and reduce unintended side effects by effectively targeting desired cells while evading immune detection. By combining the properties of biomimetic membranes and MOFs, these nanocarriers offer superior benefits such as extended circulation times, enhanced stability, and reduced immune responses. Moreover, through ligand-receptor interactions, biomimetic membrane-coated MOFs achieve homologous targeting, minimizing off-target adverse effects. The MOFs, acting as the core, efficiently encapsulate and protect siRNA molecules, while the biomimetic membrane-coated surface provides homologous targeting, further increasing the precision of siRNA delivery to cancer cells. In particular, the biomimetic membranes help to shield the MOFs from the immune system, avoiding unwanted immune responses and improving their biocompatibility. The combination of siRNA with innovative nanocarriers, such as camouflaged-MOFs, presents a significant advancement in cancer therapy. The ability to deliver siRNA with precision and effectiveness using these camouflaged nanocarriers holds great promise for achieving more personalized and efficient cancer treatments in the future. This review article discusses the significant progress made in the development of siRNA therapeutics for cancer, focusing on their effective delivery through novel nanocarriers, with a particular emphasis on the role of metal-organic frameworks (MOFs) as camouflaged nanocarriers.

Zirconium-containing nanoscale coordination polymers for positron emission tomography and fluorescence-guided cargo delivery to triple-negative breast tumors

Nanoscale coordination polymer (NCP) is a class of hybrid materials formed by self-assembly of metal ions and organic ligands through coordination. The applications of NCP in biomedicine are quite extensive due to the diversity choice of metal ions and organic ligands. Here we designed Zr-P1 NCP based on Zr4+ selected as metal ion nodes and tetrakis(4-carboxyphenyl) ethylene as bridging ligands. Zr-P1 NCP was modified with functionalized pyrene derived polyethylene glycol (Py-PAA-PEG-Mal) on the surface and further conjugated with cRGD for active targeting of integrin αvβ3 overexpressed in triple-negative breast cancer. Doxorubicin was loaded on Zr-P1 NCP with encapsulation efficiency up to 22 % for the treatment of triple negative breast cancer. 89Zr-P1 NCP can be used for in vivo tumor imaging due to the fluorescence properties resulting from the enhanced aggregation-induced Emission (AIE) behavior of P1 ligands and its positron emission tomography (PET) capability. Cellular evaluation indicated that the functionalized Zr-P1@PEG-RGD presented a good function for tumor cell targeting imaging and doxorubicin could be targeted to triple negative breast cancer when it was loaded onto Zr-P1@PEG-RGD, which corroborated with the in vivo results. In summary, 89Zr-P1@PEG-RGD can serve as a biocompatible nanoplatform for fluorescence and PET image-guided cargo delivery. STATEMENT OF SIGNIFICANCE: Nanoscale coordination polymer (NCP) is a class of hybrid materials formed by self-assembly of metal ions and organic ligands through coordination. The diversity of available metals and ligand structures upon NCP synthesis plays an advantage in establishing multimodal imaging platforms. Here we designed 89Zr-P1@PEG-RGD NCP based on Zr4+ selected as metal ion nodes and tetrakis(4-carboxyphenyl) ethylene as bridging ligands. 89Zr-P1@PEG-RGD nanomaterials have positron emission tomography (PET) capability due to the incorporation of zirconium-89, which can be used for in vivo tumor imaging with high sensitivity. The chemotherapeutic drug DOX was loaded on Zr-P1 NCP for the treatment of triple-negative breast cancer, and dual modality imaging can provide visual guidance for drug delivery.

Exclusive Coordination between Melem and Silver(I) Ions: From Irregular Aggregates to Nanofibers to Crystal Cubes

There is growing focus on metal-free molecules and polymers owing to their potential applications in various energy and catalysis-related applications. Melem (2,5,8-triamino-s-heptazine, C6H6N10) has emerged as a metal-free material for solar-to-fuel conversion. However, its reactivity with metal ions or organic molecules has never been reported although it possesses multiple supramolecular interaction sites. In this work, we report on the synthesis of a novel metal-organic coordination framework (melem-Ag) by simply introducing Ag+ into the aqueous suspension of aggregated melem particles. Notably, as the reaction progresses, the melem disappears, and the morphology of the newly formed complex spontaneously evolves from nanofibers to single-crystalline blocks, which possess the same chemical structure, indicating that the morphology evolution is driven by Ostwald ripening. The structure of melem-Ag displays infinite nanocages of triangular pyramids consisting of melem molecules and Ag+, linked via Ag-N coordinate bonding and Ag-Ag argentophilic interactions. It is noteworthy that Ag+ is the only transition-metal cation that reacts with melem suspensions, even in the presence of other transition-metal cations (Co2+, Ni2+, Cu2+, and Zn2+). The coordination of Ag+ to melem results in metal-to-ligand charge transfer (MLCT), resulting in a quenched photoluminescence and enhanced light absorption. Exposing the melem-Ag crystals to UV light for varying time intervals results in the formation of colorful powders, which may be used for Ag-decorated photocatalysts.

NIR-Light-Triggered Mild-Temperature Hyperthermia to Overcome the Cascade Cisplatin Resistance for Improved Resistant Tumor Therapy

Currently, cisplatin resistance has been recognized as a multistep cascade process for its clinical chemotherapy failure. Hitherto, it remains challenging to develop a feasible and promising strategy to overcome the cascade drug resistance (CDR) issue for achieving fundamentally improved chemotherapeutic efficacy. Herein, a novel self-assembled nanoagent is proposed, which is constructed by Pt(IV) prodrug, cyanine dye (cypate), and gadolinium ion (Gd3+), for systematically conquering the cisplatin resistance by employing near-infrared (NIR) light activated mild-temperature hyperthermia in tumor targets. The proposed nanoagents exhibit high photostability, GSH/H+-responsive dissociation, preferable photothermal conversion, and enhanced cellular uptake performance. In particular, upon 785-nm NIR light irradiation, the generated mild temperature of ≈ 43 °C overtly improves the cell membrane permeability and drug uptake, accelerates the disruption of intracellular redox balance, and apparently enhances the formation of Pt-DNA adducts, thereby effectively overcoming the CDR issue and achieves highly improved therapeutic efficacy for cisplatin-resistant tumor ablation.

Nanomaterials Regulate Bacterial Quorum Sensing: Applications, Mechanisms, and Optimization Strategies

Anti-virulence therapy that interferes with bacterial communication, known as "quorum sensing (QS)", is a promising strategy for circumventing bacterial resistance. Using nanomaterials to regulate bacterial QS in anti-virulence therapy has attracted much attention, which is mainly attributed to unique physicochemical properties and excellent designability of nanomaterials. However, bacterial QS is a dynamic and multistep process, and there are significant differences in the specific regulatory mechanisms and related influencing factors of nanomaterials in different steps of the QS process. An in-depth understanding of the specific regulatory mechanisms and related influencing factors of nanomaterials in each step can significantly optimize QS regulatory activity and enhance the development of novel nanomaterials with better comprehensive performance. Therefore, this review focuses on the mechanisms by which nanomaterials regulate bacterial QS in the signal supply (including signal synthesis, secretion, and accumulation) and signal transduction cascade (including signal perception and response) processes. Moreover, based on the two key influencing factors (i.e., the nanomaterial itself and the environment), optimization strategies to enhance the QS regulatory activity are comprehensively summarized. Collectively, applying nanomaterials to regulate bacterial QS is a promising strategy for anti-virulence therapy. This review provides reference and inspiration for further research on the anti-virulence application of nanomaterials.

Straightforward Creation of Multishell Hollow Hybrids for an Integrated Metabolic Monitoring System in Disease Management

Multidimensional metabolic analysis has become a new trend in establishing efficient disease monitoring systems, as the constraints associated with relying solely on a single dimension in refined monitoring are increasingly pronounced. Here, coordination polymers are employed as derivative precursors to create multishell hollow hybrids, developing an integrated metabolic monitoring system. Briefly, metabolic fingerprints are extracted from hundreds of serum samples and urine samples, encompassing not only membranous nephropathy but also related diseases, using high-throughput mass spectrometry. With optimized algorithm and initial feature selection, the established combined panel demonstrates enhanced accuracy in both subtype differentiation (over 98.1%) and prognostic monitoring (over 95.6%), even during double blind test. This surpasses the serum biomarker panel (≈90.7% for subtyping, ≈89.7% for prognosis) and urine biomarker panel (≈94.4% for subtyping, ≈76.5% for prognosis). Moreover, after attempting to further refine the marker panel, the blind test maintains equal sensitivity, specificity, and accuracy, showcasing a comprehensive improvement over the single-fluid approach. This underscores the remarkable effectiveness and superiority of the integrated strategy in discriminating between MN and other groups. This work has the potential to significantly advance diagnostic medicine, leading to the establishment of more effective strategies for patient management.

Recent progress on polySarcosine as an alternative to PEGylation: Synthesis and biomedical applications

Biotherapeutic PEGylation to prolong action of medications has gained popularity over the last decades. Various hydrophilic natural polymers have been developed to tackle the drawbacks of PEGylation, such as its accelerated blood clearance and non-biodegradability. Polypeptoides, such as polysarcosine (pSar), have been explored as hydrophilic substitutes for PEG. pSar has PEG-like physicochemical characteristics such as water solubility and no reported cytotoxicity and immunogenicity. This review discusses pSar derivatives, synthesis, characterization approaches, biomedical applications, in addition to the challenges and future perspectives of pSar based biomaterials as an alternative to PEG.

Recent advancements in the specific determination of carcinoembryonic antigens using MOF-based immunosensors

Carcinoembryonic antigens (CEAs) are prominent cancer biomarkers that enable the early detection of numerous cancers. For effective CEA screening, rapid, portable, efficient, and sensitive diagnosis approaches should be devised. Metal-organic frameworks (MOFs) are porous crystalline materials that have received major attention for application in high-efficiency signal probes owing to their advantages such as large specific surface area, superior chemical stability and tunability, high porosity, easy surface functional modification, and adjustable size and morphology. Immunoassay strategies using antigen-antibody specific interaction are one of the imperative means for rapid and accurate measurement of target molecules in biochemical fields. The emerging MOFs and their nanocomposites are synthesized with excellent features, providing promising potential for immunoassays. This article outlines the recent breakthroughs in the synthesis approaches of MOFs and overall functionalization mechanisms of MOFs with antigen/antibody and their uses in the CEA immunoassays, which operate according to electrochemical, electrochemiluminescent and colorimetric techniques. The prospects and limitations of the preparation and immunoassay applications of MOF-derived hybrid nanocomposites are also discussed at the end.

Strategies to address key challenges of metallacycle/metallacage-based supramolecular coordination complexes in biomedical applications

Owing to their capacity for dynamically linking two or more functional molecules, supramolecular coordination complexes (SCCs), exemplified by two-dimensional (2D) metallacycles and three-dimensional (3D) metallacages, have gained increasing significance in biomedical applications. However, their inherent hydrophobicity and self-assembly driven by heavy metal ions present common challenges in their applications. These challenges can be overcome by enhancing the aqueous solubility and in vivo circulation stability of SCCs, alongside minimizing their side effects during treatment. Addressing these challenges is crucial for advancing the fundamental research of SCCs and their subsequent clinical translation. In this review, drawing on extensive contemporary research, we offer a thorough and systematic analysis of the strategies employed by SCCs to surmount these prevalent yet pivotal obstacles. Additionally, we explore further potential challenges and prospects for the broader application of SCCs in the biomedical field.

Advances in Immunomodulatory MOFs for Biomedical Applications

Given the crucial role of immune system in the occurrence and progression of various diseases such as cancer, wound healing, bone defect, and inflammation-related diseases, immunomodulation is recognized as a potential solution for treatment of these diseases. Immunomodulation includes both immunosuppression in hyperactive immune conditions and immune activation in hypoactive conditions. For these purposes, metal-organic frameworks (MOFs) are investigated to modulate immune responses either by their own bioactivities or by delivering immunomodulatory agents due to their excellent biodegradability and high delivery capacity. This review starts with an overview of the synthesis strategies of immunomodulatory MOFs, followed by a summarization on the latest applications of immunomodulatory MOFs in cancer immunomodulatory, wound healing, inflammatory disease, and bone tissue engineering. A variety of design considerations, in order to optimize immunomodulatory properties and efficacy of MOFs, is also involved. Last, the challenges and perspectives of future research, which are expected to provide researchers with new insight into the design and application of immunomodulatory MOFs, are discussed.

NH2-MIL-101(Fe)-mediated photo-Fenton reaction enhanced simultaneous removal of nitrogen and refractory organics in anammox process through interfacial electron transfer

In this study, H2O2 (0.1 ‰) and NH2-MIL-101(Fe)-driven (150 mg/L) photo-Fenton-coupled anammox were proposed to simultaneously improve the removal efficiency of nitrogen and humic acid. Long-term experiments showed that the total nitrogen removal efficiency was increased by the photo-Fenton reaction to 91.9 ± 1.5 % by altering the bioavailability of refractory organics. Correspondingly, the total organic carbon removal efficiency was significantly increased. Microbial community analyses indicated that Candidatus_Brocadia maintained high activity during photo-Fenton reaction and was the most abundant genus in the reactor. Dissimilatory nitrate reduction to ammonium process and denitrification process were enhanced, resulting in reduced NO3--N production. The establishment of electron transfer between microorganisms and NH2-MIL-101 (Fe) improved the charge separation efficiency of the quantum dots and increased the intracellular adenosine triphosphate content of anammox bacteria. These results indicated that photo-Fenton-anammox process promoted the removal of nitrogen and refractory organics in one reactor which had good economic value and application prospects.

Recent advances in metal-organic frameworks for stimuli-responsive drug delivery

After entering the human body, drugs for treating diseases, which are prone to delivery and release in an uncontrolled manner, are affected by various factors. Based on this, many researchers utilize various microenvironmental changes encountered during drug delivery to trigger drug release and have proposed stimuli-responsive drug delivery systems. In recent years, metal-organic frameworks (MOFs) have become promising stimuli-responsive agents to release the loaded therapeutic agents at the target site to achieve more precise drug delivery due to their high drug loading, excellent biocompatibility, and high stimuli-responsiveness. The MOF-based stimuli-responsive systems can respond to various stimuli under pathological conditions at the site of the lesion, releasing the loaded therapeutic agent in a controlled manner, and improving the accuracy and safety of drug delivery. Due to the changes in different physical and chemical factors in the pathological process of diseases, the construction of stimuli-responsive systems based on MOFs has become a new direction in drug delivery and controlled release. Based on the background of the rapidly increasing attention to MOFs applied in drug delivery, we aim to review various MOF-based stimuli-responsive drug delivery systems and their response mechanisms to various stimuli. In addition, the current challenges and future perspectives of MOF-based stimuli-responsive drug delivery systems are also discussed in this review.

Nanoscale Metal-Organic Frameworks and Nanoscale Coordination Polymers: From Synthesis to Cancer Therapy and Biomedical Imaging

Recently, there has been significant interest in nanoscale metal-organic frameworks (NMOFs) characterized by ordered crystal structures and nanoscale coordination polymers (NCPs) featuring amorphous structures. These structures arise from the coordination interactions between inorganic metal ions or clusters and organic ligands. Their advantages, such as the ability to tailor composition and structure, efficiently encapsulate diverse therapeutic or imaging agents within porous frameworks, inherent biodegradability, and surface functionalization capability, position them as promising carriers in the biomedical fields. This review provides an overview of the synthesis and surface modification strategies employed for NMOFs and NCPs, along with their applications in cancer treatment and biological imaging. Finally, future directions and challenges associated with the utilization of NMOFs and NCPs in cancer treatment and diagnosis are also discussed.

Luminescent lanthanide-based molecular materials: applications in photodynamic therapy

Luminescent lanthanide molecular compounds have recently attracted attention as potential photosensitizers (PSs) for photodynamic therapy (PDT) against malignant cancer tumours because of their predictable systemic toxicity, temporospatial specificity, and minimal invasiveness. A photosensitizer exhibits no toxicity by itself, but in the presence of light and oxygen molecules, it can generate reactive oxygen species (ROS) to cause damage to proteins, nucleic acids, lipids, membranes, and organelles, which can induce cell apoptosis. This review focuses on the latest developments in luminescent lanthanide-based molecular materials as photosensitizers and their applications in photodynamic therapy. These molecular materials include lanthanide coordination complexes, nanoscale lanthanide coordination polymers, and lanthanide-based nanoscale metal-organic frameworks. In the end, the future challenges in the development of robust luminescent lanthanide molecular materials-based photosensitisers are outlined and emphasized to inspire the design of a new generation of phototheranostic agents.

Adsorption and photocatalytic applications of porphyrin-based materials for environmental separation processes: A review

As society progresses and industrializes, the issue of water pollution, caused by a wide array of organic and inorganic pollutants, poses significant risks to both human well-being and the environment. Given its distinctive characteristics, water pollution has become a paramount concern for society, necessitating immediate attention. Numerous studies have been conducted on wastewater treatment, primarily focusing on two key approaches: adsorption and photocatalytic degradation. Adsorption offers unparalleled advantages, including its simplicity, high removal efficiency, and cost-effectiveness. Conversely, photocatalysis harnesses abundant, clean, and non-polluting sunlight, addressing the critical issue of energy scarcity. Porphyrins, which are macrocyclic tetrapyrrole derivatives found widely in nature, have attracted growing interest in recent years. These lipophilic pigments exhibit remarkable chemical stability and have retained their major structural features for up to 1.1 billion years. As such, they are considered vital indicators of life and have been extensively studied, from the remnants of extinct organisms to gain insights into the principles of evolution. Porphyrins are often associated with a central metal ion within their ring system and can be modified through various substituents, including additional rings or ring opening, resulting in a wide range of functionalities. This comprehensive review summarizes recent advancements in the field of porphyrins. It begins by introducing the structures and preparation methods of porphyrins. Subsequently, it delves into notable applications of porphyrins in the context of pollutant adsorption in water and their environmentally friendly photocatalytic degradation.

Smart, degradable, and eco-friendly carboxymethyl cellulose-CaII hydrogel-like networks gated MIL-101(FeIII) nanoherbicides for paraquat delivery

Nanopesticides have been selected as one of the top 10 chemical innovations for enhancing the efficacy and safety of agrochemicals. Herein, smart, degradable, and eco-friendly metal-organic framework MIL-101(FeIII) nanoherbicides coated with carboxymethyl cellulose-CaII (CMC-CaII) cross-linking hydrogel-like networks are synthesized via a simple strategy. The coating of the CMC-CaII hydrogel-like gatekeepers is oriented by the coordination unsaturated FeIII clusters on the surfaces of the MIL-101(FeIII) nanocarriers to form a dense film network to prevent paraquat (PQ) leakage. Based on the stimuli factors (acid/basic pH, GSH, phosphates, and EDTA) of physiological and natural environments of target plants, the nanoherbicides are combined with five stimuli-responsive properties to attain the various controlled release of packaged PQ by the disassembly of the gatekeepers and/or the degradation of the MOF skeleton structure. More importantly, based on the stimuli-responsive controlled release mechanisms, the eco-friendly nanocarriers are ultimately degraded against bioaccumulation in plants or soil. The coating of natural CMC could promote the spreading of PQ owing to improvement of wettability for aqueous droplets of nanoherbicides on hydrophobic foliage. The PQ trapped in nanocarriers can effectively prevent PQ degradation, which showed that cumulative degradation rate is ca. 2.6 times lower than that of technical PQ under UV irradiation. The prepared nanoherbicides loaded with PQ show good control efficacy against weeds by controlling the release of PQ; good safety on seed germination (germination rate 97.32-99.67 %), seedling emergence (emergence rate 95.53-99.67 %), and are beneficial for the growth of wheat seedling (increase rate of plant height 1.89-6.97 % and 0.54-5.67 % after 7 and 15 days of seedling emergence, respectively) in the greenhouse; good biosafety for honeybees (Apis mellifera L.), which shows that lethal rates were 2.04 and 2.55 times lower than technical PQ for incubation 24 and 48 h, respectively. The nanoherbicides have potential applications in the field for PQ green agriculture.

Nanoreactor-based catalytic systems for therapeutic applications: Principles, strategies, and challenges

Inspired by natural catalytic compartments, various synthetic compartments that seclude catalytic reactions have been developed to understand complex multistep biosynthetic pathways, bestow therapeutic effects, or extend biosynthetic pathways in living cells. These emerging nanoreactors possessed many advantages over conventional biomedicine, such as good catalytic activity, specificity, and sustainability. In the past decade, a great number of efficient catalytic systems based on diverse nanoreactors (polymer vesicles, liposome, polymer micelles, inorganic-organic hybrid materials, MOFs, etc.) have been designed and employed to initiate in situ catalyzed chemical reactions for therapy. This review aims to present the recent progress in the development of catalytic systems based on nanoreactors for therapeutic applications, with a special emphasis on the principles and design strategies. Besides, the key components of nanoreactor-based catalytic systems, including nanocarriers, triggers or energy inputs, and products, are respectively introduced and discussed in detail. Challenges and prospects in the fabrication of therapeutic catalytic nanoreactors are also discussed as a conclusion to this review. We believe that catalytic nanoreactors will play an increasingly important role in modern biomedicine, with improved therapeutic performance and minimal side effects.

Polymer architecture dictates multiple relaxation processes in soft networks with two orthogonal dynamic bonds

Materials with tunable modulus, viscosity, and complex viscoelastic spectra are crucial in applications such as self-healing, additive manufacturing, and energy damping. It is still challenging to predictively design polymer networks with hierarchical relaxation processes, as many competing factors affect dynamics. Here, networks with both pendant and telechelic architecture are synthesized with mixed orthogonal dynamic bonds to understand how the network connectivity and bond exchange mechanisms govern the overall relaxation spectrum. A hydrogen-bonding group and a vitrimeric dynamic crosslinker are combined into the same network, and multimodal relaxation is observed in both pendant and telechelic networks. This is in stark contrast to similar networks where two dynamic bonds share the same exchange mechanism. With the incorporation of orthogonal dynamic bonds, the mixed network also demonstrates excellent damping and improved mechanical properties. In addition, two relaxation processes arise when only hydrogen-bond exchange is present, and both modes are retained in the mixed dynamic networks. This work provides molecular insights for the predictive design of hierarchical dynamics in soft materials.

Hierarchical MOF@AuNP/Hairpin Nanotheranostic for Enhanced Photodynamic Therapy via O2 Self-Supply and Cancer-Related MicroRNA Imaging In Vivo

Developing a nanotheranostic with a high sensing performance and efficient therapy was significant in cancer diagnosis and treatment. Herein, a Au nanoparticle and hairpin-loaded photosensitive metal-organic framework (PMOF@AuNP/hairpin) nanotheranostic was constructed by growing AuNPs on PMOF in situ and then attaching hairpins. On the one hand, the PMOF@AuNP/hairpin nanotheranostic could effectively transfer O2 into ROS, facilitating efficient PDT. Additionally, the nanotheranostic possessed catalase-like activity, which could effectively catalyze H2O2 to generate O2, thus achieving O2-evolving PDT and significantly enhancing the antitumor effect of PDT in vivo. On the other hand, the nanotheranostic showed a high loading efficiency of hairpins and achieved the sensitive and selective detection of miR-21 both in living cells and in vivo. Moreover, the nanotheranostic could dynamically monitor the miR-21 level. Due to the excellent imaging performance, the nanotheranostic could recognize cancer cells and might provide important information on cancer progression for PDT. The developed PMOF@AuNP/hairpin nanotheranostic provided a useful tool for tumor diagnosis and antitumor therapy.

A simple one step synthesis of magnetic-optical dual functional ZIF-8 in a sodalite phase for magnetically guided targeting bioimaging and drug delivery

Functionalized metal-organic frameworks (MOFs) that integrate targeted tumor imaging and drug delivery are expected to significantly enhance the therapeutic efficacy of cancer. However, the complicated synthesis process has greatly limited their utilization in clinical application. Herein, a one-step simple method was used to construct novel multifunctional MOFs by co-loading doxorubicin (DOX) and Fe3O4 into the ZIF-8 with sodalite topology. DOX serves as a fluorescence imaging reagent and an anticancer drug and Fe3O4 is used as a magnetic resonance imaging and magnetic targeting anticancer reagent. The fabricated DOX/Fe3O4@ZIF-8 nanocomposite showed excellent fluorescence and magnetic resonance imaging performances in tumors. Moreover, DOX/Fe3O4@ZIF-8 can be accumulated in tumors via a magnetic targeting effect and tumor growth could be inhibited in vivo due to the release of DOX. Additionally, the apoptosis process of DOX/Fe3O4@ZIF-8 on HepG2 cells is well investigated. Overall, DOX/Fe3O4@ZIF-8 synthesized in simple one step can be used for simultaneous targeted bioimaging and cancer therapy.

Nanoscale coordination polymer Fe-DMY downregulating Poldip2-Nox4-H2O2 pathway and alleviating diabetic retinopathy

Diabetic retinopathy (DR) is a prevalent microvascular complication of diabetes and the leading cause of blindness and severe visual impairment in adults. The high levels of glucose trigger multiple intracellular oxidative stress pathways, such as POLDIP2, resulting in excessive reactive oxygen species (ROS) production and increased expression of vascular cell adhesion molecule-1 (VCAM-1), hypoxia-inducible factor 1α (HIF-1α), and vascular endothelial growth factor (VEGF), causing microvascular dysfunction. Dihydromyricetin (DMY) is a natural flavonoid small molecule antioxidant. However, it exhibits poor solubility in physiological environments, has a short half-life in vivo, and has low oral bioavailability. In this study, we present, for the first time, the synthesis of ultra-small Fe-DMY nano-coordinated polymer particles (Fe-DMY NCPs), formed by combining DMY with low-toxicity iron ions. In vitro and in vivo experiments confirm that Fe-DMY NCPs alleviate oxidative stress-induced damage to vascular endothelial cells by high glucose, scavenge excess ROS, and improve pathological features of DR, such as retinal vascular leakage and neovascularization. Mechanistic validation indicates that Fe-DMY NCPs can inhibit the activation of the Poldip2-Nox4-H2O2 signaling pathway and downregulate vital vascular function indicators such as VCAM-1, HIF-1α, and VEGF. These findings suggest that Fe-DMY NCPs could serve as a safe and effective antioxidant and microangio-protective agent, with the potential as a novel multimeric drug for DR therapy.

A biocompatible pure organic porous nanocage for enhanced photodynamic therapy

Porphyrin-based photosensitizers have been widely utilized in photodynamic therapy (PDT), but they suffer from deteriorating fluorescence and reactive oxygen species (ROS) due to their close π-π stacking. Herein, a biocompatible pure organic porphyrin nanocage (Py-Cage) with enhanced both type I and type II ROS generation is reported for PDT. The porphyrin skeleton within the Py-Cage is spatially separated by four biphenyls to avoid the close π-π stacking within the nanocage. The Py-Cage showed a large cavity and high porosity with a Brunauer-Emmett-Teller surface area of over 300 m2 g-1, facilitating a close contact between the Py-Cage and oxygen, as well as the fast release of ROS to the surrounding microenvironment. The Py-Cage shows superb ROS generation performance over its precursors and commercial ones such as Chlorin E6 and Rose Bengal. Intriguingly, the cationic π-conjugated Py-Cage also shows promising type I ROS (superoxide and hydroxyl radicals) generation that is more promising for hypoxic tumor treatment. Both in vitro cell and in vivo animal experiments further confirm the excellent antitumor activity of the Py-Cage. As compared to conventional metal coordination approaches to improve PDT efficacy of porphyrin derivatives, the pure organic porous Py-Cage demonstrates excellent biocompatibility, which is further verified in both mice and rats. This work of an organic porous nanocage shall provide a new paradigm for the design of novel, biocompatible and effective photosensitizers for PDT.

Advance Progress in Assembly Mechanisms of Carrier-Free Nanodrugs for Cancer Treatment

Nanocarriers have been widely studied and applied in the field of cancer treatment. However, conventional nanocarriers still suffer from complicated preparation processes, low drug loading, and potential toxicity of carriers themselves. To tackle the hindrance, carrier-free nanodrugs with biological activity have received increasing attention in cancer therapy. Extensive efforts have been made to exploit new self-assembly methods and mechanisms to expand the scope of carrier-free nanodrugs with enhanced therapeutic performance. In this review, we summarize the advanced progress and applications of carrier-free nanodrugs based on different types of assembly mechanisms and strategies, which involved noncovalent interactions, a combination of covalent bonds and noncovalent interactions, and metal ions-coordinated self-assembly. These carrier-free nanodrugs are introduced in detail according to their assembly and antitumor applications. Finally, the prospects and existing challenges of carrier-free nanodrugs in future development and clinical application are discussed. We hope that this comprehensive review will provide new insights into the rational design of more effective carrier-free nanodrug systems and advancing clinical cancer and other diseases (e.g., bacterial infections) infection treatment.

Nitric Oxide: Physiological Functions, Delivery, and Biomedical Applications

Nitric oxide (NO) is a gaseous molecule that has a central role in signaling pathways involved in numerous physiological processes (e.g., vasodilation, neurotransmission, inflammation, apoptosis, and tumor growth). Due to its gaseous form, NO has a short half-life, and its physiology role is concentration dependent, often restricting its function to a target site. Providing NO from an external source is beneficial in promoting cellular functions and treatment of different pathological conditions. Hence, the multifaceted role of NO in physiology and pathology has garnered massive interest in developing strategies to deliver exogenous NO for the treatment of various regenerative and biomedical complexities. NO-releasing platforms or donors capable of delivering NO in a controlled and sustained manner to target tissues or organs have advanced in the past few decades. This review article discusses in detail the generation of NO via the enzymatic functions of NO synthase as well as from NO donors and the multiple biological and pathological processes that NO modulates. The methods for incorporating of NO donors into diverse biomaterials including physical, chemical, or supramolecular techniques are summarized. Then, these NO-releasing platforms are highlighted in terms of advancing treatment strategies for various medical problems.

Theoretical and Experimental Advances in High-Pressure Behaviors of Nanoparticles

Using compressive mechanical forces, such as pressure, to induce crystallographic phase transitions and mesostructural changes while modulating material properties in nanoparticles (NPs) is a unique way to discover new phase behaviors, create novel nanostructures, and study emerging properties that are difficult to achieve under conventional conditions. In recent decades, NPs of a plethora of chemical compositions, sizes, shapes, surface ligands, and self-assembled mesostructures have been studied under pressure by in-situ scattering and/or spectroscopy techniques. As a result, the fundamental knowledge of pressure-structure-property relationships has been significantly improved, leading to a better understanding of the design guidelines for nanomaterial synthesis. In the present review, we discuss experimental progress in NP high-pressure research conducted primarily over roughly the past four years on semiconductor NPs, metal and metal oxide NPs, and perovskite NPs. We focus on the pressure-induced behaviors of NPs at both the atomic- and mesoscales, inorganic NP property changes upon compression, and the structural and property transitions of perovskite NPs under pressure. We further discuss in depth progress on molecular modeling, including simulations of ligand behavior, phase-change chalcogenides, layered transition metal dichalcogenides, boron nitride, and inorganic and hybrid organic-inorganic perovskites NPs. These models now provide both mechanistic explanations of experimental observations and predictive guidelines for future experimental design. We conclude with a summary and our insights on future directions for exploration of nanomaterial phase transition, coupling, growth, and nanoelectronic and photonic properties.

Reticular Chemistry for Optical Sensing of Anions

In the last few decades, reticular chemistry has grown significantly as a field of porous crystalline molecular materials. Scientists have attempted to create the ideal platform for analyzing distinct anions based on optical sensing techniques (chromogenic and fluorogenic) by assembling different metal-containing units with suitable organic linking molecules and different organic molecules to produce crystalline porous materials. This study presents novel platforms for anion recognition based on reticular chemistry with high selectivity, sensitivity, electronic tunability, structural recognition, strong emission, and thermal and chemical stability. The key materials for reticular chemistry, Metal-Organic Frameworks (MOFs), Zeolitic Imidazolate Frameworks (ZIFs), and Covalent-Organic Frameworks (COFs), and the pre- and post-synthetic modification of the linkers and the metal oxide clusters for the selective detection of the anions, have been discussed. The mechanisms involved in sensing are also discussed.

Metal-organic framework based drug delivery systems as smart carriers for release of poorly soluble drugs hydrochlorothiazide and dapsone

Drug delivery systems (DDSs) that are derived from biocompatible carriers are attractive platforms for sustained release of drugs. In particular, sustained and controlled release of poorly soluble BCS (Biopharmaceutics Classification System) class IV drugs is important and this requires the development of new DDSs. In this work, we exploit two porous metal-organic frameworks (MOFs) MIL-100(Fe) and MIL-53(Fe) as carriers/DDSs for the release of two BCS class IV drugs hydrochlorothiazide (HCT) and dapsone (DAP). The chosen MOFs are known to possess good physicochemical stability and we realized high drug loading capacity that is attributed to the high porosity of the MOFs. The drug-encapsulated MOFs were characterized thoroughly and our results show ∼23.1% loading of HCT in MIL-100(Fe) and ∼27.6% loading of DAP in MIL-Fe(53), respectively. The release study of these drugs was carried out under simulated physiological conditions that shows sustained release of the drug molecules from the MOFs up to 72 h. Cell viability studies through MTT assays show insignificant cytotoxicity signalling biocompatibility of the proposed DDSs. Our investigations suggest MIL-100(Fe) and MIL-53(Fe) are potential DDSs for enhancing the performance of poorly soluble drugs HCT and DAP.

Harnessing Hafnium-Based Nanomaterials for Cancer Diagnosis and Therapy

With the rapid development of nanotechnology and nanomedicine, there are great interests in employing nanomaterials to improve the efficiency of disease diagnosis and treatment. The clinical translation of hafnium oxide (HfO2 ), commercially namedas NBTXR3, as a new kind of nanoradiosensitizer for radiotherapy (RT) of cancers has aroused extensive interest in researches on Hf-based nanomaterials for biomedical application. In the past 20 years, Hf-based nanomaterials have emerged as potential and important nanomedicine for computed tomography (CT)-involved bioimaging and RT-associated cancer treatment due to their excellent electronic structures and intrinsic physiochemical properties. In this review, a bibliometric analysis method is employed to summarize the progress on the synthesis technology of various Hf-based nanomaterials, including HfO2 , HfO2 -based compounds, and Hf-organic ligand coordination hybrids, such as metal-organic frameworks or nanoscaled coordination polymers. Moreover, current states in the application of Hf-based CT-involved contrasts for tissue imaging or cancer diagnosis are reviewed in detail. Importantly, the recent advances in Hf-based nanomaterials-mediated radiosensitization and synergistic RT with other current mainstream treatments are also generalized. Finally, current challenges and future perspectives of Hf-based nanomaterials with a view to maximize their great potential in the research of translational medicine are also discussed.

Peroxidase-like oxidative activity of cobalt-based 1D coordination polymer; experimental and theoretical investigations

CONTEXT

The present work describes the synthesis, structural characterization, and catalytic activity of a Co(II)-based one-dimensional coordination polymer (CP1). To validate the chemotherapeutic potential of CP1, in vitro DNA binding assessment was carried out by employing multispectroscopic techniques. Moreover, the catalytic activity of CP1 was also ascertained during the oxidative conversion of o-phenylenediamine (OPD) to diaminophenazine (DAP) under aerobic conditions.

METHODS

The molecular structure of CP1 was solved with the olex2.solve structure solution program using charge flipping and refined with the olex2.refine refinement package by using Gauss-Newton minimization. The DFT studies were performed by utilizing ORCA Program Version 4.1.1 to calculate the electronic and chemical properties of CP1 by calculating the HOMO-LUMO energy gap. All calculations were carried out at B3LYP hybrid functional using def2-TZVP as the basis set. Contour plots of various FMOs were visualized by using Avogadro software. Hirshfeld surface analysis was carried out by Crystal explorer Program 17.5.27 to examine the various non-covalent interactions which are crucial for the stability of crystal lattice. In addition, molecular docking studies of CP1 with DNA were performed by using AutoDock Vina software and AutoDock tools (version 1.5.6). Discovery studio 3.5 Client 2020 was used for visualization of the docked pose and binding interactions of CP1 with ct-DNA.

Photothermal and Catalytic Performance of Multifunctional Cu-Fe Bimetallic Prussian Blue Nanocubes with the Assistance of Near-Infrared Radiation

Copper and iron are the basic metal elements that have attracted much attention in industry. Prussian blue (PB) is a significant class of metal-organic frameworks (MOFs); however, the lack of such linkages between the structure and properties, as well as properties differences, limits their potential applications. In this paper, the Cu-based Prussian blue nanocubes with and without Fe doping were synthesized. With the increasing reaction time, the morphology of the Cu-based Prussian blue nanocubes without Fe doping (PB:Cu NCs) changes from cuboidal to circular, and finally grows back to cuboidal. However, Cu-based Prussian blue nanocubes with Fe doping (PB: CuFe NCs) grow directly from the cube and eventually collapse. The nanocubes show a notable red shift with the tunable spectra from 400 nm to 700 nm. Compared with PB: Cu NCs, the PB: CuFe NCs have higher temperature rise under 808 nm irradiation and better photothermal efficacy. The catalytic efficiency of PB: CuFe NCs changes with the pH and reaches its maximum value of 1.021 mM with a pH of 5.5. The enhanced catalytic reaction by the near-infrared radiation plasmonic photothermal effect is also confirmed. This work highlights the potential of the developed PB: Cu and PB: CuFe NCs for photothermal-enhanced co-catalysis nanomaterials.

Metal organic frameworks-in-nanochannels: A tailorable chromatography membrane for isolation of target protein

Metal-organic frameworks (MOFs) demonstrate strong potential in biosample separation. However, the obtained MOFs powders are unsuitable for recovery techniques in an aqueous solution, especially the challenges of withdrawing MOFs particles and expanding their functions for specific applications. Herein, a general strategy is designed utilizing metal oxide-nanochannel arrays as precursors and templates for in-situ selective growth of MOFs structures. The exemplary MOFs (Ni-bipy) with tailored composition are selectively grown in NiO/TiO₂ nanochannel membrane (NM) using NiO as the sacrificial precursor, which enables one to achieve a ∼262 times concentration of histidine-tagged proteins within 100 min. The significantly improved adsorption efficiency in a wide pH range and the effective enrichment from a complex matrix as a nanofilter illustrate the great potential of MOFs in nanochannels membranes for the high-efficiency recovery of essential proteins in complex biological samples. The porous self-aligned Ni-MOFs/TiO₂ NM exhibits biocompatibility and flexible functionalities, which is desirable for the generation of multifunctional nanofilter devices and developing biomacromolecule delivery vehicles.

Silane-Functionalized Metal-Organic Frameworks for Stimuli-Responsive Drug Delivery Systems: A New Universal Strategy

A new universal strategy for silane functionalization of metal-organic frameworks (MOFs) was developed. It was demonstrated that silanes were coupled both with terminal hydroxyl (OH) groups and with bridging OH groups of metal-oxo clusters of MOFs through condensation reactions between the silanols of hydrolyzed silanes and the terminal/bridging OH groups to form metal-O-Si bonds. A wide variety of functionalization of MOFs with conventional silanes can be realized by combining synthesis reactions in the solution phase and chemical modifications on the surface. Multivalent supramolecular nanovalves based on the host-guest chemistry of cyclodextrin polymer (CDP) and benzimidazole stalks silanized on the nanoscale MOF (NMOF) surface were successfully constructed. The CDP-valved NMOFs showed the excellent performance of low pH- and α-amylase-responsive controlled drug release. In vitro and in vivo results demonstrated that the CDP-valved NMOFs had a significant inhibitory effect on tumor growth and almost no damage/toxicity to normal tissues. The silanization strategy is universal and opens up a new way for the functionalization of MOFs, which are endowed with a wide variety of applications spanning gas storage, chemical sensing, adsorption and separation, heterogeneous catalysis, and drug delivery.

Synergetic argentophilic and through space electronic interactions in a single-crystal-to-single-crystal photocycloaddition reaction: a mechanistic study

Ag(I) is able to mediate single-crystal-to-single-crystal transformation through [2+2] photocycloaddition to prepare high-conductivity materials. However, the intrinsic mechanism of Ag(I) mediation, the detailed photophysical and photochemical processes as well as the origin of the enhanced conductivity of nanocrystals are still unclear. In this work, the comprehensive kinetic scheme and regulation mechanism are established by the accurate QM/MM calculations at the CASPT2//CASSCF/AMBER level of theory with consideration of the crystal environment. We find that the argentophilic interaction and through space electronic interaction are the key factors that promote Ag(I)-mediated [2+2] PCA reactions and may account for the enhancement of conductivity. These mechanistic insights into the Ag(I)-regulated photo-dimerization in the crystal surrounding are beneficial for the design of the structurally and electrically favorable skeletons of a metal-organic coordination polymer.

In Response to Precision Medicine: Current Subcellular Targeting Strategies for Cancer Therapy

Emerging as a potent anticancer treatment, subcellular targeted cancer therapy has drawn increasing attention, bringing great opportunities for clinical application. Here, two targeting strategies for four main subcellular organelles (mitochondria, lysosome, endoplasmic reticulum, and nucleus), including molecule- and nanomaterial (inorganic nanoparticles, micelles, organic polymers, and others)-based targeted delivery or therapeutic strategies, are summarized. Phototherapy, chemotherapy, radiotherapy, immunotherapy, and "all-in-one" combination therapy are among the strategies covered in detail. Such materials are constructed based on the specific properties and relevant mechanisms of organelles, enabling the elimination of tumors by inducing dysfunction in the corresponding organelles or destroying specific structures. The challenges faced by organelle-targeting cancer therapies are also summarized. Looking forward, a paradigm for organelle-targeting therapy with enhanced therapeutic efficacy compared to current clinical approaches is envisioned.

Poly-thymine DNA templated MnO2 biomineralization as a high-affinity anchoring enabling tumor targeting delivery

Manganese oxide nanomaterials (MONs) are emerging as a type of highly promising nanomaterials for diseases diagnosis, and surface modification is the basis for colloidal stability and targeting delivery of the nanomaterials. Here, we report the in-situ functionalization of MnO₂ with DNA through a biomineralization process. Using adsorption-oxidation method, DNA templated Mn²⁺ precursor to biomineralize into nano-cubic seed, followed by the growth of MnO₂ to form cube/nanosheet hybrid nanostructure. Among four types of DNA homopolymers, poly-thymine (poly-T) was found to stably attach on MnO₂ surface to resist various biological displacements (phosphate, serum, and complementary DNA). Capitalized on this finding, a di-block DNA was rationally designed, in which the poly-T block stably anchored on MnO₂ surface, while the AS1411 aptamer block was not only an active ligand for tumor targeting delivery, but also a carrier for photosensitizer (Ce6) loading. Upon targeting delivery into tumor cells, the MnO₂ acted as catalase-mimic nanozyme for oxygenation to sensitize photodynamic therapy, and the released Mn²⁺ triggered chemodynamic therapy via Fenton-like reaction, achieving synergistic anti-tumor effect with full biocompatibility. This work provides a simple yet robust strategy to functionalize metal oxides nanomaterials for biological applications via DNA-templated biomineralization.

Preparation and Characterization of a Coordination Polymer Based on Iron (III)-Cyamelurate as a Superior Catalyst for Heterogeneous Fenton-Like Processes

We report on a new iron (iii)-cyamelurate-based coordination polymer. The new material based on a heptazine derivative was prepared in aqueous medium and characterized by a variety of techniques including TGA, FTIR, XRD, HRTEM, and STEM. Due to the high structural stability of the complex in aqueous media, its heterogeneous Fenton-like catalytic activity was evaluated using a model molecule. The results obtained showed a high catalytic activity in both in basic and acid media. The pseudo-first-order rate constants normalized by iron(III) concentrations was approximately 1000 times higher than the result obtained for traditional heterogeneous catalysts based on iron(III) oxyhydroxides. The best observed catalytic activities were attributed to the increase in the binding sites of Fe³⁺ ions, in parallel with the increased exposure of the catalytic sites, leading to a higher atomic efficiency of the reaction.

Aptamer modified Zr-based porphyrinic nanoscale metal-organic frameworks for active-targeted chemo-photodynamic therapy of tumors

Active-targeted nanoplatforms could specifically target tumors compared to normal cells, making them a promising therapeutic agent. The aptamer is a kind of short DNA or RNA sequence that can specifically bind to target molecules, and could be widely used as the active targeting agents of nanoplatforms to achieve active-targeted therapy of tumors. Herein, an aptamer modified nanoplatform DOX@PCN@Apt-M was designed for active-targeted chemo-photodynamic therapy of tumors. Zr-based porphyrinic nanoscale metal organic framework PCN-224 was synthesized through a one-pot reaction, which could produce cytotoxic ¹O₂ for efficient treatment of tumor cells. To improve the therapeutic effect of the tumor, the anticancer drug doxorubicin (DOX) was loaded into PCN-224 to form DOX@PCN-224 for tumor combination therapy. Active-targeted combination therapy achieved by modifying the MUC1 aptamer (Apt-M) onto DOX@PCN-224 surface can not only further reduce the dosage of therapeutic agents, but also reduce their toxic and side effects on normal tissues. In vitro, experimental results indicated that DOX@PCN@Apt-M exhibited enhanced combined therapeutic effect and active targeting efficiency under 808 nm laser irradiation for MCF-7 tumor cells. Based on PCN-224 nanocarriers and aptamer MUC1, this work provides a novel strategy for precisely targeting MCF-7 tumor cells.

Unraveling mitochondria-targeting reactive oxygen species modulation and their implementations in cancer therapy by nanomaterials

Functional subcellular organelle mitochondria are emerging as a crucial player and driver of cancer. For maintaining the sites of cellular respiration, mitochondria experience production, and accumulation of reactive oxygen species (ROS) underlying oxidative damage in electron transport chain carriers. Precision medicine targeting mitochondria can change nutrient availability and redox homeostasis in cancer cells, which might represent a promising strategy for suppressing tumor growth. Herein, this review highlights how the modification capable of manipulating nanomaterials for ROS generation strategies can influence or compensate the state of mitochondrial redox homeostasis. We propose foresight to guide research and innovation with an overview of seminal work and discuss future challenges and our perspective on the commercialization of novel mitochondria-targeting agents.

A Mechanically Reinforced Super Bone Glue Makes a Leap in Hard Tissue Strong Adhesion and Augmented Bone Regeneration

Existing bone tissue engineering strategies aim to achieve minimize surgical trauma, stabilize the injured area, and establish a dynamic osteogenic microenvironment. The cutting-edge bone glue developed in this study satisfies these criteria. Inspired by the excellent adhesive properties of mussels, herein, a super osteogenic glue (L-DPZ) that integrates poly(vinyl alcohol), L-dopa amino acid, and zeolitic imidazolate framework-8 characterized by catechol-metal coordination is used to successfully adhere to hard tissue with a maximum adhesive strength of 10 MPa, which is much higher than those of commercial and previously reported bone glues. The stable hard tissue adhesion also enables it to adhere strongly to luxated or broken teeth, Bio-Oss (a typical bone graft material), and splice fragments from comminuted fractures of the rabbit femur. Then, it is testified that the L-DPZ hydrogels exhibit satisfactory biocompatibility, stable degradability, and osteogenic ability in vitro. Moreover, the ability to anchor Bio-Oss and sustained osteogenesis of L-DPZ result in satisfactory healing in calvarial bone defect models in rabbits, as observed by increased bone thickness and the ingrowth of new bone tissue. These results are expected to demonstrate solutions to clinical dilemmas such as comminuted bone fracture fixation, bone defect reconstruction, and teeth dislocation replantation.

A Novel "Inside-Out" Intraocular Nanomedicine Delivery Mode for Nanomaterials' Biological Effect Enhanced Choroidal Neovascularization Occlusion and Microenvironment Regulation

Photodynamic therapy (PDT) is commonly used in choroidal neovascularization (CNV) treatment due to the superior light transmittance of the eye. However, PDT often leads to surrounding tissue damage and further microenvironmental deterioration, including exacerbated hypoxia, inflammation, and secondary neovascularization. In this work, Pt nanoparticles (NPs) and Au NPs decorated zeolitic imidazolate framework-8 nanoplatform is developed to load indocyanine green for precise PDT and microenvironment amelioration, which can penetrate the internal limiting membrane through Müller cells endocytosis and target to CNV by surface-grafted cyclo(Arg-Gly-Asp-d-Phe-Lys) after intravitreal injection. The excessive H₂ O₂ in the CNV microenvironment is catalyzed by catalase-like Pt NPs for hypoxia relief and enhanced PDT occlusion of neovascular. Meanwhile, Au NPs show significant anti-inflammatory and anti-angiogenesis properties in regulating macrophages and blocking vascular endothelial growth factor (VEGF). Compared with verteporfin treatment, the mRNA expressions of hypoxia-inducible factor-1α and VEGF in the nanoplatform group are downregulated by 90.2% and 81.7%, respectively. Therefore, the nanoplatform realizes a comprehensive CNV treatment effect based on the high drug loading capacity and biosafety. The CNV treatment mode developed in this work provides a valuable reference for treating other diseases with similar physiological barriers that limit drug delivery and similar microenvironment.